5/30/2003 - Trimble (NASDAQ:TRMB) announced it has supplied Global Positioning System (GPS) reference stations and VRSTM (Virtual Reference Station) software to the Seismological Bureau of Sichuan Province in China to establish a VRS network around the city of Chengdu. The multi-purpose network around Chengdu, the capital of the Sichuan Province, provides high-precision GPS data for monitoring the Earth's crustal movement and for surveying and construction work; the network will also provide correction data for real-time kinematic (RTK) GPS users in the future.

The Sichuan Province VRS installation follows other Trimble infrastructure projects, including: the Japanese Geographical Survey Institute (GSI) Nationwide Network; VRS network in Switzerland for the Swiss government; GPSnet.dk, the VRS network in Denmark; the Queensland, Australia VRS network; GPS reference stations for the General Lighthouse Authority Network around the coast of Great Britain; the Channel Tunnel Rail Link RTK Network; and the Zurich International Airport Expansion Project.

"Trimble's real-time infrastructure technologies provide major benefits in productivity, ease-of-use and consistency of results for survey, mapping and construction professionals worldwide," said Nancy Nelson, division vice president of Infrastructure for the Trimble Geomatics and Engineering Division. "High accuracy position information is economically provided for multiple applications such as single-person surveying, construction stakeout, hydrographic work, GIS mapping and crustal deformation monitoring."

About the Sichuan Province VRS
The Sichuan Province VRS network is an enhancement to its current GPS monitoring network project which is supported by the local provincial government as a central part of their efforts to digitize Chengdu city.

The GPS network consists of eight Trimble 5700 Continuously Operating Reference Station (CORS) GPS receivers with ZephyrTM Geodetic antennae and GPSNetTM, RTKNetTM, Web server software and a communications infrastructure. Four of the 5700 CORS are used as permanent base stations; the other four are temporary post processing stations.

VRS technology overcomes previous limitations with high precision GPS by utilizing data from a network of reference stations to model the error sources within the network. The system significantly reduces these systematic errors to improve reliability and operating range. Standard format RTK messages are transmitted via GSM cellar telephones to users in the field within the network area. This allows a user to increase the distance at which the rover receiver is located from the physical reference stations while improving on-the-fly (OTF) initialization times.

Traditionally, for precise GPS applications-surveying, construction, precision farming and high accuracy Geographic Information System (GIS)-roving receivers required a reference station within 10 kilometers to ensure centimeter level accuracy. With VRS, users within the network can operate consistently at greater distances without degrading accuracy. Productivity is increased as a single individual can operate anytime in a common coordinate system without the need to set up a temporary reference station with it's associated costs and the likelihood for introduction of errors.

Additionally, users can retrieve stored GPS and modeled data from the control center via the Internet for post-processing. Trimble Terrasat developed the VRS software suite.

About the Seismological Bureau of Sichuan Province
The Seismological Bureau of Sichuan Province is a branch of the China Seismological Bureau. As a leading seismic research agency in the Peoples Republic of China, the Seismological Bureau of Sichuan Province has been deeply involved in GPS crust monitoring project in China since 1998.

About the Trimble Geomatics and Engineering Division
Trimble, a world leader in GPS, robotic total stations and machine control solutions, is creating a broad range of innovative solutions that will change the way surveying and construction work is done. The Geomatics and Engineering Division is focusing on the development of technology and solutions in the core areas of surveying, construction and infrastructure. From concept to completion, Trimble's integrated systems streamline jobs and improve productivity.

About Trimble
Trimble is a leading innovator of Global Positioning System (GPS) technology. In addition to providing advanced GPS components, Trimble augments GPS with other positioning technologies as well as wireless communications and software to create complete customer solutions. Trimble's worldwide presence and unique capabilities position the Company for growth in emerging applications including surveying, automobile navigation, machine guidance, asset tracking, wireless platforms, and telecommunications infrastructure. Founded in 1978 and headquartered in Sunnyvale, Calif., Trimble has more than 2,000 employees in more than 20 countries worldwide.